Synthesis 2005(3): 397-402  
DOI: 10.1055/s-2005-861782
PAPER
© Georg Thieme Verlag Stuttgart · New York

N-(Cbz- and Fmoc-α-aminoacyl)benzotriazoles: Stable Derivatives Enabling Peptide Coupling of Tyr, Trp, Cys, Met, and Gln with Free Amino Acids in Aqueous Media with Complete Retention of Chirality

Alan R. Katritzky*, Parul Angrish, Deniz Hür, Kazuyuki Suzuki
Center for Heterocyclic Compounds, Department of Chemistry, University of Florida, Gainesville, FL 32611-7200, USA
e-Mail: katritzky@chem.ufl.edu;
Further Information

Publication History

Received 12 October 2004
Publication Date:
18 January 2005 (online)

Abstract

Crystalline, chirally stable N-(Cbz- and Fmoc-α-amino­acyl)benzotriazoles 2a-f, activated derivatives of Tyr, Trp, Cys, Met and Gln undergo peptide coupling in aqueous media with unprotected l-Ala-OH and l-Phe-OH to give the chiral dipeptides in 70-98% yield. A convenient and efficient procedure under mild reaction conditions for the preparation of 2a-f in 72-95% yield utilizes N-Cbz- or N-Fmoc-protected α-amino acids 1a-f.